attn Joe or anyone who can help with Idle and acceleration problem 92 Johnson 150

[trooper]

" I put the boat in the water this weekend, but it would not stay running. When first starting it would idle fine for adout 30 sec and begin to decrease RPM and then spit sneeze once and cut off. Once up and going it ran fine at mid to full RPM but would not idle long and died out on acceleration from idle.

The compression is 112-120 psi on all cylinders new omc fuel bulb with straight through fitting (no anti-siphon valve). The VRO and pulse limiter are new and I think the carbs are clean.

I took the boat to the shop and they told me if there were no fuel problems it could be the Labyrinth seals or sometimes called seal rings letting fuel get from one cylinder to the back of the piston on another cylinder, causing it to sneeze and cut-off. The shop said, "if it was the seals I would need a new motor $8,000.00. Yikes!

Does anyone know what these seals are and if this is likely to be the problem ? What if any alternatives do I have to get fishing again?

Thanks in advance for the help,

Jack Nienke "

[joereeves]

"Jack.... You don't say how long you've owned this engine, or when it last ran properly. However, if you've owned it for a year or so, and if when you last used it, it ran properly.... and since then it has been sitting for a couple months or more, I would strongly suspect that the carburetors are clogged/fouled/gummed in such a manner that a restriction exists that is interfering with the slow speed passageways. That would result in the exact problem as you explain it.

There are "Seal Rings" on the crankshaft, seperating one cylinder from another, (a engineering design that has existed since 1958), but I have never seen one fail in any respect, other than engines that have been under water (salt water). Bottom line is, I don't buy that seal ring story!

You can check the carburetor theory by removing the carburetor face plate cover, run the engine at idle (after a warm up), then one after another, stick two fingers into the carb throats. When you hit a clogged/fouled carburetor, the engine will smooth out somewhat, and the rpms will increase (Usually more than one carb, but it could be just one).

Is there another dealership/marine mechanic in your area? If so, discuss the problem with them and see if they will rebuild the carbs for you if that appears to be the problem.

Joe[img][/img]"

[trooper]

" Joe thanks a million or at least $8,000 worth. I have owned the boat and motor for about 4.5 years and it is never been in salt water to my knowledge. The boat did run great about 3 weeks ago, then I decided to do some preventive maintenance. I changed the fuel line/bulb and replaced the orginal VRO with the pulse limiter included. The boat ran fine on a flushette device, infact I thought the idle was too high, but when put in the water the boat would not idle and bogged on acceleration. Anyway, the shop did not say the seal rings were bad only that if they could not find any other reason for the problem, that they would suspect the seal rings and to expect to pay $8,000 for a motor. You have made me feel much better about my situation. I will sleep good tonight.
Thanks,
Jack "